System for managing mobile internet protocol addresses in an airborne wireless cellular network

ABSTRACT

The Aircraft Mobile IP Address System provides wireless communication services to passengers who are located onboard an aircraft by storing data indicative of the individually identified wireless devices located onboard the aircraft. The System assigns a single IP address to each Point-to-Point Protocol link which connects the aircraft network to the ground-based communication network but also creates an IP subnet onboard the aircraft. The IP subnet utilizes a plurality of IP addresses for each Point-to-Point link thereby to enable each passenger wireless device to be uniquely identified with their own IP address. This is enabled since both Point-to-Point Protocol IPCP endpoints have pre-defined IP address pools and/or topology configured; each Point-to-Point Protocol endpoint can utilize a greater number of IP addresses than one per link. Such an approach does not change IPCP or other EVDO protocols/messaging but does allow this address to be directly visible to the ground-based communication network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/060,645 filed Apr. 1, 2008.

FIELD OF THE INVENTION

This invention relates to cellular communications and, in particular, toa system that creates an Internet Protocol based subnet on board anaircraft in an airborne wireless cellular network.

BACKGROUND OF THE INVENTION

It is a problem in the field of wireless communications to manage thewireless services provided by an aircraft network to passengers who arelocated in the aircraft as they roam among cell sites in thenon-terrestrial cellular communication network. The aircraft networkserves a plurality of subscribers, yet has a link to the ground-basednetwork via a wide bandwidth connection that concurrently servesmultiple individual subscribers. The management of this wide bandwidthconnection to enable the individual identification of aircraft-basedsubscribers has yet to be addressed in existing wireless networks.

In the field of terrestrial cellular communications, it is common for awireless subscriber to move throughout the area served by the network oftheir home cellular service provider and maintain their desiredsubscriber feature set. Feature set availability throughout the homenetwork is managed by the home cellular service provider's database,often termed a Home Location Register (HLR), with data connections toone or more switches (packet or circuit), and various ancillaryequipment, such as voice mail and short message servers, to enable thisseamless feature set management. Each subscriber is associated with aone-to-one communication connection, which comprises a channel on theserving cell site, to access the desired communication services.

If the wireless subscriber were to transition inter-network from thecoverage area of their home cellular network to a network of the same oranother cellular service provider (termed “roaming cellular serviceprovider” herein), the wireless subscriber should have the ability tooriginate and receive calls in a unified manner, regardless of theirlocation. In addition, it should be possible for a given wirelesssubscriber's feature set to move transparently with them. However, forthis feature set transportability to occur, there needs to be databasefile sharing wherein the home cellular service Home Location Register(HLR) transfers the subscriber's authorized feature set profile to theroaming cellular service provider's database, often called a VisitorLocation Register, or VLR. The VLR then recognizes that a given roamingwireless subscriber is authorized for a certain feature set and enablesthe roaming cellular service provider network to transparently offerthese features to the wireless subscriber. In this manner, the roamingwireless subscriber retains the same authorized feature set, or“subscriber class”, as they had on their home cellular service providernetwork.

When wireless subscribers enter the non-terrestrial cellularcommunication network (that is, they fly in an aircraft as passengers),they encounter a unique environment that traditionally has beendisconnected from the terrestrial cellular network, where the wirelessnetwork of the aircraft interfaces the subscriber (also termed“passenger” herein) to various services and content. The aircraftwireless network, therefore, can function as a content filter or cancreate unique types of content that are directed to the individualpassengers who are onboard the aircraft. However, although the aircraftnetwork serves a plurality of passengers, it has a link to theground-based Access Network via a wide bandwidth radio frequencyconnection that has a single IP address on the ground-based AccessNetwork. Thus, the wide bandwidth radio frequency connectionconcurrently carries the communications of multiple individualpassengers, but these communications cannot be individually identifiedby the ground-based Access Network. The management of this widebandwidth connection to enable the individual identification ofpassengers via the assignment of individual unique IP addresses to eachpassenger wireless device has yet to be addressed in existing wirelessnetworks.

BRIEF SUMMARY OF THE INVENTION

The above-described problems are solved and a technical advance achievedin the field by the present System For Managing Mobile Internet ProtocolAddresses In An Airborne Wireless Cellular Network (termed “AircraftMobile IP Address System” herein), which enables the assignment ofindividual Internet Protocol (IP) addresses to each of the passengerwireless devices, operating in an aircraft and served by an airbornewireless cellular network, thereby to enable delivery of wirelessservices to the individually identified passenger wireless devices.

The Aircraft Mobile IP Address System provides wireless communicationservices to passengers who are located onboard an aircraft by storingdata indicative of the individually identified wireless devices that arelocated onboard the aircraft. The Aircraft Mobile IP Address Systemassigns a single IP address either to each Air-to-Ground Modem in theAir-to-Ground Communications Unit which terminates the radio frequencylink which connects the aircraft network to the ground-based AccessNetwork, or the MIP client that executes on the Air-to-Ground ControlProcessor Unit located behind these Air-to-Ground Modems. A thirdapproach is to dispense with the use of a Mobile IP Client and to useSimple IP Addresses and an IP Tunnel to connect the aircraft network tothe ground-based Access Network. Such an approach does not change IPCPor other EVDO protocols/messaging but does allow the wireless deviceindividual IP address to be directly visible to the ground-based AccessNetwork.

The electronic services that are provided to the passenger includeInternet, in-flight entertainment services, such as multi-mediapresentations, as well as destination-based services, which link thepassenger's existing travel plans with offers for additional servicesthat are available to the passenger at their nominal destination andtheir planned travel schedule, and optionally, voice services. Thepassenger thereby is presented with opportunities during their flight toenhance their travel experience, both in-flight and at theirdestination, by accessing the various services. The individualidentification of each passenger wireless device simplifies theprovision of these services and enables the customization of theseservices based upon predefined profiles created for the passenger.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates, in block diagram form, the overall architecture of acomposite air-to-ground network that interconnects an Air Subsystem witha Ground-Based Access Network;

FIG. 2 illustrates, in block diagram form, the architecture of a typicalembodiment of a typical aircraft-based network for wireless devices asembodied in a multi-passenger commercial aircraft;

FIGS. 3A and 3B illustrate, in block diagram form, the architecture of atypical EVDO cellular network for IP data only service and for IP dataand voice services, respectively;

FIG. 4 illustrates, in block diagram form, the architecture of animplementation of the Aircraft Mobile IP Address System which providesmobile IP addresses within the EVDO Network;

FIG. 5 illustrates, in block diagram form, the architecture of animplementation of the Aircraft Mobile IP Address System which providesmobile IP addresses outside of the EVDO Network using a Mobile IPtunnel;

FIG. 6 illustrates typical addressing used in the system of FIG. 5;

FIG. 7 illustrates the transfer of an IP Tunnel between Air-to-GroundModems with the change in typical addressing used in the system of FIG.6; and

FIG. 8 illustrates, in block diagram form, the architecture of animplementation of the Aircraft Mobile IP Address System which providesmobile IP addresses outside of the EVDO Network using IP tunnels.

DETAILED DESCRIPTION OF THE INVENTION Overall System Architecture

FIG. 1 illustrates, in block diagram form, the overall architecture ofthe non-terrestrial cellular communication network, which includes anAir-To-Ground Network 2 (Inner Network) that interconnects the twoelements of an Outer Network, comprising an Air Subsystem 3 and GroundSubsystem 1. This diagram illustrates the basic concepts of thenon-terrestrial cellular communication network and, for the purpose ofsimplicity of illustration, does not comprise all of the elements foundin a typical non-terrestrial cellular communication network. Thefundamental elements disclosed in FIG. 1 provide a teaching of theinterrelationship of the various elements which are used to implement anon-terrestrial cellular communication network to provide content topassenger wireless devices which are located in an aircraft.

The overall concept illustrated in FIG. 1 is the provision of an “InnerNetwork” that connects the two segments of the “Outer Network”,comprising the Air Subsystem 3 and the Ground Subsystem 1. This isaccomplished by the Air-To-Ground Network 2 transmitting both thepassenger communication traffic (comprising voice and/or other data) andcontrol information and feature set data between the Air Subsystem 3 andthe Ground Subsystem 1 thereby to enable the passenger wireless devicesthat are located in the aircraft to receive services in the aircraft.

Air Subsystem

The “Air Subsystem” is the communications environment that isimplemented in the aircraft, and these communications can be based onvarious technologies including, but not limited to: wired, wireless,optical, acoustic (ultrasonic), and the like. An example of such anetwork is disclosed in U.S. Pat. No. 6,788,935, titled “Aircraft-BasedNetwork For Wireless Subscriber Stations”.

The preferred embodiment for the Air Subsystem 3 is the use of wirelesstechnology and for the wireless technology to be native to the passengerwireless devices that passengers and crew carry on the aircraft. Thus, alaptop computer can communicate via a WiFi or WiMax wireless mode (orvia a wired connection, such as a LAN), or a PDA could communicatetelephony voice traffic via VoIP (Voice over IP). Likewise, a hand-heldcell phone that uses the GSM protocol communicates via GSM when insidethe aircraft to the Air Subsystem. A CDMA cell phone would use CDMA, andan analog AMPS phone would use analog AMPS when inside the aircraft tothe Air Subsystem 3. The connection states could be packet -switched orcircuit -switched or both. Overall, the objective on the Air Subsystem 3is to enable seamless and ubiquitous access to the Air Subsystem 3 forthe passenger wireless devices that are carried by passengers and crew,regardless of the technology used by these wireless devices.

The Air Subsystem 3 also provides the mechanism to manage the provisionof services to the passenger wireless devices that are operating in theaircraft cabin. This management includes not only providing thepassenger traffic connectivity but also the availability ofnon-terrestrial specific feature sets which each passenger is authorizedto receive. These features include in-flight entertainment services,such as multi-media presentations, as well as destination-based serviceswhich link the passenger's existing travel plans with offers foradditional services that are available to the passenger at their nominaldestination and their planned travel schedule. The passenger thereby ispresented with opportunities during their flight to enhance their travelexperience, both in-flight and at their destination.

The passenger wireless devices 101 used in the aircraft can be identicalto those used on the cellular/PCS ground-based communication network;however, these passenger wireless devices 101 are pre-registered withthe carrier serving the aircraft, and/or users have PIN numbers forauthentication. In addition, an antenna interconnects the passengerwireless devices 101 with the in-cabin Base Transceiver Stations (BTS)111-114, which are typically pico-cells with BSC/MSC functionsintegrated. BTS/BSC/MSC modules are added for each air-interfacetechnology supported. The Switch/Router 122 acts as the bridgingfunction (for media/content and signaling to a limited extent) betweenthe Air Subsystem 3 and the ground-based Access Network 1, since theSwitch/Router 122 places a call using the Modem 123 to the ground-basedAccess Network 1 via the Air-To-Ground Network 2. Switch/Router 122converts the individual traffic and signaling channels from the basestations to/from an aggregate data stream and transmits/receives theaggregate data streams over the Air-to-Ground Network 2 which maintainscontinuous service as the aircraft travels. The Modem 123 includes radiotransmission equipment and antenna systems to communicate withground-based transceivers in the ground-based portion of theAir-to-Ground Network 2. The individual traffic channels assigned on theAir-to-Ground Network 2 are activated based upon the traffic demand tobe supported from the aircraft.

Air-To-Ground Network

The Air-to-Ground Network 2 shown in FIG. 1 is clearly one that is basedon wireless communications (radio frequency or optical) between theGround Subsystem 1 and the passenger wireless devices 101 that arelocated in the aircraft, with the preferred approach being that of aradio frequency connection. This radio frequency connection takes on theform of a cellular topology where typically more than one cell describesthe geographic footprint or coverage area of the composite Air-To-GroundNetwork 2. The air-to ground connection carries both passengercommunications traffic and native network signaling traffic. In thepreferred embodiment, the Air-to-Ground Network 2 transports all trafficto/from the aircraft in a single, aggregated communication channel. This“single pipe” has distinct advantages in terms of managing hard and softhandoffs as the aircraft transitions between one ground-based cell tothe next. This approach also takes advantage of newer, higher speedwireless cellular technologies.

Alternatively, the Air-To-Ground Network 2 could be achieved through awireless satellite connection where radio frequency links areestablished between the aircraft and a satellite and between thesatellite and the Ground Subsystem 1, respectively. These satellitescould be geosynchronous (appears to be stationary from an earthreference point) or moving, as is the case for Medium Earth Orbit (MEO)and Low Earth Orbit (LEO). Examples of satellites include, but are notlimited to: Geosynchronous Ku Band satellites, DBS satellites (DirectBroadcast Satellite), the Iridium system, the Globalstar system, and theInmarsat system. In the case of specialized satellites, such as thoseused for Direct Broadcast Satellite, the link typically isunidirectional, that is, from the satellite to the receiving platform,in this case an aircraft. In such a system, a link transmittingunidirectionally from the aircraft is needed to make the communicationbidirectional. This link could be satellite or ground-based wireless innature as previously described. Last, other means for communicating toan aircraft include broad or wide area links such as HF (High Frequency)radio and more unique systems such as troposcatter architectures.

The Air-To-Ground Network 2 can be viewed as the conduit through whichthe passenger communications traffic, as well as the control and networkfeature set data, is transported between the Ground Subsystem 1 and theAir Subsystem 3. The Air-To-Ground Network 2 can be implemented as asingle radio frequency link or multiple radio frequency links, with aportion of the signals being routed over different types of links, suchas the Air-To-Ground Link and the Satellite Link. Thus, there is asignificant amount of flexibility in the implementation of this system,using the various components and architectural concepts disclosed hereinin various combinations.

The radio frequency design for the Air-To-Ground Modem typically usesmultiple modems, where one Air-To-Ground Modem (Air-to-Ground Modem 1)operates with a Vertical signal polarization and one Air-To-Ground Modem(Air-to-Ground Modem 2) operates with a Horizontal signal polarization,and as signal strength is lost/gained on the individual Air-To-GroundModems, that Air-To-Ground Modem becomes dormant or active.

In a first embodiment of this protocol, the Air-To-Ground Modems are notassigned an IP address, but there is a Mobile IP Client on theAir-To-Ground Communications Unit with a Forward Address on the PublicData Switched Network. This Mobile IP Client is configured with a HomeAddress and registers with a corresponding Foreign Address/Home Addressto associate a Home Address with Air-To-Ground Modem1 or Air-To-GroundModem2 on the Public Data Switched Network/Foreign Address. The HomeAddress to Care of Address (subnet address) association does not change,since the Care of Address is the Public Data Switched Network IP addressand managed in the Public Data Switched Network. The Mobile IP Client onthe Air-To-Ground Communications Unit requires information from theAir-To-Ground Modem to update Mobile IP bindings on Foreign Address/HomeAddress. The Mobile IP Client must receive Air-To-Ground Modem1 andAir-To-Ground Modem 2 Assigned IP (this is the Care of Address for theMobile IP Client). The Mobile IP Client shall have configured/known HomeAddress and Home Agent Server Address. This configuration can runmultiple Mobile IP Clients and tunnels on the Air-To-GroundCommunications Unit.

In a second embodiment of this protocol, the Air-To-Ground Modems areeach assigned an IP address and the Mobile IP Client resides on theAir-To-Ground Control Processor Unit. This Mobile IP Client isconfigured with a Home Address, and a corresponding Care of Address isassociated with Air-To-Ground Modem1 or Air-To-Ground Modem2 in theAir-To-Ground Communications Unit. The Mobile IP Client on theAir-To-Ground Control Processor Unit is connected via a Mobile IP Tunnelto the Public Data Switched Network. The traffic is switched between thetwo Air-To-Ground Modems as signal strength is lost/gained on theindividual Air-To-Ground Modems.

In a third embodiment of this protocol, the Air-To-Ground Modems areeach assigned an IP address, and Simple IP Addresses are managed on theAir-To-Ground Communications Unit. Multiple IP Tunnels connect theAir-To-Ground Control Processor Unit to a Router in the ground-basedAccess Network. The Air-To-Ground Control Processor Unit performs thetunnel endpoint functions and uses a Public Address for these IPTunnels. The traffic is switched between the two Air-To-Ground Modems assignal strength is lost/gained on the individual Air-To-Ground Modems.

Ground Subsystem

The Ground Subsystem 1 consists of Edge Router 140 which connects thevoice traffic of the Air-To-Ground Network 2 with traditional cellularcommunication network elements, including a Base Station Controller 141and its associated Mobile Switching Center 142 with its Visited LocationRegister, Home Location Register to interconnect the voice traffic tothe Public Switched Telephone Network 144, and other suchfunctionalities. In addition, the Base Station Controller 141 isconnected to the Internet 147 via Public Switched Data Network 143 forcall completions. Edge Router 124 also provides interconnection of thedata traffic to the Internet 147, Public Switched Telephone Network 144via Voice Over IP Server 146, and other such functionalities. Theseinclude the Authentication Server, Operating Subsystems, CALEA, and BSSservers 145.

Thus, the communications between the passenger wireless devices 101located in an aircraft and the Ground Subsystem 1 of the ground-basedcommunication network are transported via the Air Subsystem 3 and theAir-To-Ground Network 2 to the ground-based Base Station Controllers 141of the non-terrestrial cellular communication network. The enhancedfunctionality described below and provided by the Air Subsystem 3, theAir-To-Ground Network 2, and the ground-based Base Station Controllers141 renders the provision of services to the passenger wireless devices101 located in an aircraft transparent to the passengers. The RadioAccess Network (RAN) supports communications from multiple aircraft andmay employ a single omni-directional signal, or may employ multiplespatial sectors which may be defined in terms of azimuth and/orelevation angles. Aircraft networks hand over the Point-to-Pointcommunication links between Radio Access Networks (RAN) in differentlocations (different Ground Subsystems 1), in order to maintaincontinuity of service on Air-to-Ground Network 2. Handovers may be hardor soft, or may be a combination of hard and soft on the air-ground andground-air links.

The Mobile Switching Center (MSC) provides mobility management for allairborne systems and provides handover management between groundstations as an airborne system moves between the service areas ofadjoining Ground Subsystems 1. The Base Station Controller (BSC)interfaces all traffic to/from the Base Transceiver Subsystem (BTS). ThePacket Data Serving Node (PDSN) controls assignment of capacity of eachof the Base Transceiver Subsystems (BTS) among the airborne systemswithin their respective service areas.

Typical Aircraft-Based Network

FIG. 2 illustrates the architecture of a typical aircraft-based networkfor passenger wireless devices as embodied in a multi-passengercommercial aircraft 200. This system comprises a plurality of elementsused to implement a communication backbone that is used to enablewireless communication for a plurality of wireless communication devicesof diverse nature. The aircraft-based network for passenger wirelessdevices comprises a Local Area Network 206 that includes a radiofrequency communication system 201 that uses a spread spectrum paradigmand having a short range of operation. This network 206 supports bothcircuit-switched and packet-switched connections from passenger wirelessdevices 221-224 and interconnects the communications of these passengerwireless devices 221-224 via a gateway transceiver or transceivers 210to the Public Switched Telephone Network (PSTN) 126 and otherdestinations, such as the Internet 127 or Public Data Switched Network(PDSN). The wireless passengers thereby retain their single numberidentity as if they were directly connected to the Public SwitchedTelephone Network 126. The passenger wireless devices 221-224 include adiversity of communication devices, such as laptop computers 221,cellular telephones 222, MP3 music players (not shown), Personal DigitalAssistants (PDA) (not shown), WiFi-based devices 223, WiMax-baseddevices 224, and the like, and for simplicity of description are allcollectively termed “passenger wireless devices” herein, regardless oftheir implementation-specific details.

The basic elements of the aircraft-based network for passenger wirelessdevices comprises at least one antenna 205 or means of couplingelectromagnetic energy to/from the Air Subsystem 3 located within theaircraft 200 which serves to communicate with the plurality of passengerwireless devices 221-224 located within the aircraft 200. The at leastone antenna 205 is connected to a wireless controller 201 thatencompasses a plurality of elements that serve to regulate the wirelesscommunications with the plurality of passenger wireless devices 221-224.The wireless controller 201 includes at least one low power radiofrequency transceiver 202 for providing a circuit switched communicationspace using a wireless communication paradigm, such as PCS, CDMA, orGSM, for example. In addition, the wireless controller 201 includes alow power radio frequency transceiver 203 for providing a data-basedpacket -switched communication space using a wireless communicationparadigm, such as WiFi (which could also convey packet -switched Voiceover Internet Protocol (VoIP)).

Finally, the wireless controller 201 includes a power control segment204 that serves to regulate the power output of the plurality ofpassenger wireless devices. It also serves, by RF noise or jammingapparatus, to prevent In-Cabin passenger wireless devices from directlyand errantly accessing the ground network when in a non-terrestrialmode. The ultra-low airborne transmit power levels feature represents acontrol by the Power Control element 204 of the wireless controller 201of the aircraft-based network for passenger wireless devices to regulatethe output signal power produced by the passenger wireless devices221-224 to minimize the likelihood of receipt of a cellular signal byground-based cell sites or ground-based wireless devices.

It is obvious that these above-noted segments of the wireless controller201 can be combined or parsed in various ways to produce animplementation that differs from that disclosed herein. The particularimplementation described is selected for the purpose of illustrating theconcept of the invention and is not intended to limit the applicabilityof this concept to other implementations.

The wireless controller 201 is connected via a backbone network 206 to aplurality of other elements which serve to provide services to thepassenger wireless devices 221-224. These other elements can include anAircraft Interface 209 (which includes the “Air-To-Ground CommunicationsUnit” and the “Air-To-Ground Control Processor Unit”) for providingmanagement, switching, routing, and aggregation functions for thecommunication transmissions of the passenger wireless devices. A dataacquisition element 207 serves to interface with a plurality of flightsystem sensors 211-214 and a Global Positioning System element 216 tocollect data from a plurality of sources as described below.Furthermore, pilot communication devices, such as the display 217 andheadset 218, are connected to this backbone network 206 either via awired connection or a wireless connection.

Finally, a gateway transceiver(s) 210 is used to interconnect theAircraft Interface 209 to an antenna 215 to enable signals to betransmitted via link 108 from the aircraft-based network for passengerwireless devices 221-224 to transceivers located on the ground. Includedin these components is a communications router function to forward thecommunication signals to the proper destinations. Thus, signals that aredestined for passengers on the aircraft are routed to these individuals,while signals routed to passengers located, for example, on the groundare routed to the Ground Subsystem. Aircraft antenna patterns thattypically minimize nadir (Earth directed) effective radiated power (ERP)may be used in the implementation of the antenna(s) 215 on the aircraftto serve the aircraft-based network for passenger wireless devices221-224.

Passenger Login For System Access

On each aircraft, the passenger access to electronic communicationstypically is regulated via a passenger's wireless device registrationprocess, where each electronic device must be identified, authenticated,and authorized to receive service. Since the aircraft is aself-contained environment with respect to the wireless communicationsbetween the passenger wireless devices and the airborne wireless networkextant in the aircraft, all communications are regulated by the networkcontroller. Thus, when a passenger activates their passenger's wirelessdevice, a communication session is initiated between the passenger'swireless device and the network controller to identify the type ofdevice the passenger is using and, thus, its wireless protocol. A“splash screen” is delivered to the passenger on their wireless deviceto announce entry into the wireless network portal. Once this isestablished, the network controller transmits a set of login displays tothe passenger's wireless device to enable the passenger to identifythemselves and validate their identity (if the passenger's wirelessdevice is not equipped to automatically perform these tasks via a smartclient which automatically logs the passenger into the network). As aresult of this process, the passenger's wireless device is provided witha unique electronic identification (IP address), and the network canrespond to the passenger's wireless device without furtheradministrative overhead. The authentication process may include the useof security processes, such as a password, scan of a passenger immutablecharacteristic (fingerprint, retina scan, etc.), and the like.

Once the passenger's wireless device is logged in, the passenger canaccess the free standard electronic services that are available from thenetwork or customized electronic services for the particular passenger.The screens that are presented to the passengers can be customized topresent the branding of the airline on which the passenger is traveling.

Mobile Wireless Network Architecture

For simplicity of description, the following example is based upon theuse of a CDMA2000 EVDO cellular network paradigm. However, the conceptsillustrated herein are not limited to this implementation, and it isexpected that other implementations can be created based upon othernetwork architectures and implementations. Therefore, FIGS. 3A and 3Billustrate, in block diagram form, the architecture of a typical EVDOcellular network for IP data only service and for IP data and voiceservices, respectively, and which are used to illustrate thearchitecture and operation of the present Aircraft Mobile IP AddressSystem. CDMA2000 is a hybrid 2.5G/3G technology of mobiletelecommunications that uses CDMA (code division multiple access) tosend digital radio, voice, data, and signaling data between wirelessdevices and cell sites. The architecture and operation of the CDMA2000cellular network is standardized by the 3rd Generation PartnershipProject 2 (3GPP2). In a CDMA2000 cellular network, two Radio AccessNetwork technologies are supported: 1xRTT and EV-DO (Evolution-DataOptimized), wherein CDMA2000 is considered a third generation (3G)technology when the EV-DO Access Network is used.

The CDMA 2000 cellular network (also termed “Access Network” herein)comprises three major parts: the core network (CN), the Radio AccessNetwork (RAN), and the wireless device (MS). The core network (CN) isfurther decomposed in two parts, one interfacing to external networkssuch as the Public Switched Telephone Network (PSTN) and the otherinterfacing to an IP based network such as the Internet 311 and/orprivate data networks 312. The wireless device MS terminates the radiopath on the user side of the cellular network and enables subscribers toaccess network services over the interface Um implemented tointerconnect the wireless device (MS) with the Access Network 300.

Several key components of the Access Network 300 for IP data only asillustrated in FIG. 3A are:

-   -   Base Transceiver System (BTS): an entity that provides        transmission capabilities across the Um reference point. The        Base Transceiver System (BTS) consists of radio devices,        antenna, and equipment.    -   Base Station Controller (BSC): an entity that provides control        and management for one or more Base Transceiver Systems (BTS).    -   Packet Control Function (PCF): an entity that provides the        interface function to the packet -switched network (Internet 311        and/or Private Data Network 312).

The wireless device (MS) functions as a mobile IP client. The wirelessdevice (MS) interacts with the Access Network 300 to obtain appropriateradio resources for the exchange of packets and keeps track of thestatus of radio resources (e.g., active, stand-by, dormant). Thewireless device (MS) accepts buffer packets from the Base TransceiverSystem (BTS) when radio resources are not in place or are insufficientto support the flow to the Access Network 300. Upon power-up, thewireless device (MS) automatically registers with the Home LocationRegister (HLR) in the Mobile Switching Center (MSC) in order to:

-   -   Authenticate the wireless device (MS) for the environment of the        accessed network;    -   Provide the Home Location Register (HLR) with the wireless        device's present location; and    -   Provide the Serving Mobile Switching Center (MSC) with the        wireless device's permitted feature set.

After successfully registering with the Home Location Register (HLR),the wireless device (MS) is ready to place voice and data calls. Thesemay take either of two forms, Circuit-Switched Data (CSD) orPacket-Switched Data (PSD), depending on the wireless device's owncompliance (or lack thereof) with the IS-2000 standard.

Wireless devices must comply with IS-2000 standards to initiate a packetdata session using the Access Network 300. Wireless devices which haveonly IS-95 capabilities are limited to Circuit -Switched Datatransmitted via the Public Switched Telephone Network (PSTN), whileIS-2000 terminals can select either the Packet-Switched Data orCircuit-Switched Data. Parameters forwarded by the wireless device (MS)over the air link (AL) to the Access Network 300 determine the type ofservice requested. For each data session, a Point-to-Point Protocol(PPP) session is created between the wireless device (MS) and the PacketData Serving Node (PDSN). IP address assignment for each wireless devicecan be provided by either the Packet Data Serving Node (PDSN) or aDynamic Host Configuration Protocol (DHCP) server via a Home Agent (HA).

The Radio Access Network (RAN)

The Radio Access Network (RAN) is the wireless device's entry point forcommunicating either data or voice content. It consists of:

-   -   The air link (AL);    -   The cell site tower/antenna and the cable connection to the Base        Transceiver Subsystem (BTS);    -   The Base Transceiver Subsystem (BTS);    -   The communications path from the Base Transceiver Subsystem to        the Base Station Controller (BSC);    -   The Base Station Controller (BSC); and    -   The Packet Control Function (PCF).

The Radio Access Network (RAN) has a number of responsibilities thatimpact the network's delivery of packet services in particular. TheRadio Access Network (RAN) must map the mobile client identifierreference to a unique link layer identifier used to communicate with thePacket Data Serving Node (PDSN), validate the wireless device for accessservice, and maintain the established transmission links.

The Base Transceiver Subsystem (BTS) controls the activities of the airlink (AL) and acts as the interface between the Access Network 300 andthe wireless device (MS). Radio Frequency resources such as frequencyassignments, sector separation, and transmit power control are managedat the Base Transceiver Subsystem (BTS). In addition, the BaseTransceiver Subsystem (BTS) manages the back-haul from the cell site tothe Base Station Controller (BSC) to minimize any delays between thesetwo elements.

The Base Station Controller (BSC) routes voice- and circuit-switcheddata messages between the cell sites and the Mobile Switching Center(MSC). It also bears responsibility for mobility management: it controlsand directs handoffs from one cell site to another as needed.

The Packet Control Function (PCF) routes IP packet data between themobile station (MS) within the cell sites and the Packet Data ServingNode (PDSN). During packet data sessions, it assigns availablesupplemental channels as needed to comply with the services requested bythe wireless device (MS) and paid for by the subscribers.

Packet Data Serving Node (PDSN)

The Packet Data Serving Node (PDSN) is the gateway from the Radio AccessNetwork (RAN) into the public and/or private packet networks. In asimple IP network, the Packet Data Serving Node (PDSN) acts as astandalone Network Access Server (NAS); in a mobile IP network, it canbe configured as a Home Agent (HA) or a Foreign Agent (FA). The PacketData Serving Node (PDSN) implements the following activities:

-   -   Manage the radio-packet interface between the Base Station        Subsystem (BTS), the Base Station Controller (BSC), and the IP        network by establishing, maintaining, and terminating link layer        to the mobile client;    -   Terminate the Point-to-Point Protocol (PPP) session initiated by        the subscriber;    -   Provide an IP address for the subscriber (either from an        internal pool or through a Dynamic Host Configuration Protocol        (DHCP) server or through an Authentication, Authorization, and        Accounting (AAA) server);    -   Perform packet routing to external packet data networks or        packet routing to the Home Agent (HA) which optionally can be        via secure tunnels;    -   Collect and forward packet billing data;    -   Actively manage subscriber services based on the profile        information received from the SCS server of the Authentication,        Authorization, and Accounting (AAA) server; and    -   Authenticate users locally, or forward authentication requests        to the Authentication, Authorization, and Accounting (AAA)        server.

Authentication, Authorization, And Accounting Server

The Authentication, Authorization, and Accounting (AAA) server is usedto authenticate and authorize subscribers for network access and tostore subscriber usage statistics for billing and invoicing.

The Home Agent

The Home Agent (HA) supports seamless data roaming into other networksthat support 1xRTT. The Home Agent (HA) provides an anchor IP addressfor the mobile system and forwards any mobile-bound traffic to theappropriate network for delivery to the handset. It also maintains userregistration, redirects packets to the Packet Data Serving Node (PDSN),and (optionally) tunnels securely to the Packet Data Serving Node(PDSN). Lastly, the Home Agent (HA) supports dynamic assignment of usersfrom the Authentication, Authorization, and Accounting (AAA) server and(again optionally) assigns dynamic home addresses.

Traditional Single Call Setup In A CDMA2000 Access Network

A successful call set-up scenario for a single wireless device toestablish a communication connection in a CDMA2000 Access Network isdescribed below. Note that this explanation bypasses the radioreception/transmission activities of the Base Transceiver Subsystem(BTS), concentrating instead on the protocol functions that begin withthe Origination dialogue between the wireless device (MS) and the BaseStation Controller (BSC):

-   -   1. To register for packet data services, the wireless device        (MS) sends an Origination Message over the Access Channel to the        Base Station Subsystem (BSS).    -   2. The Base Station Subsystem (BSS) acknowledges the receipt of        the Origination Message, returning a Base Station Acknowledgment        Order to the wireless device (MS).    -   3. The Base Station Subsystem (BSS) constructs a CM Service        Request message and sends the message to the Mobile Switching        Center (MSC).    -   4. The Mobile Switching Center (MSC) sends an Assignment Request        message to the Base Station Subsystem (BSS) requesting        assignment of radio resources. No terrestrial circuit between        the Mobile Switching Center (MSC) and the Base Station Subsystem        (BSS) is assigned to the packet data call.    -   5. The Base Station Subsystem (BSS) and the wireless device (MS)        perform radio resource set-up procedures. The Packet Control        Function (PCF) recognizes that no A10 connection associated with        this wireless device (MS) is available and selects a Packet Data        Serving Node (PDSN) for this data call. The A10 connection is a        term defined by the standards bodies and refers to an Interface        between Base Station Controller (BSC) and the Packet Data        Serving Node (PDSN), where A10 references IP user data exchanged        between the Base Station Controller (BSC) and the Packet Data        Serving Node (PDSN).    -   6. The Packet Control Function (PCF) sends an A11-Registration        Request message to the selected Packet Data Serving Node (PDSN).    -   7. The A11-Registration Request is validated, and the Packet        Data Serving Node (PDSN) accepts the connection by returning an        A11-Registration

Reply message. Both the Packet Data Serving Node (PDSN) and the PacketControl Function (PCF) create a binding record for the A10 connection.The term “A11” references signaling exchanged between the Base StationController (BSC) and the Packet Data Serving Node (PDSN).

-   -   8. After both the radio link and the A10 connection are set up,        the Base Station Subsystem (BSS) sends an Assignment Complete        message to the Mobile Switching Center (MSC).    -   9. The mobile system and the Packet Data Serving Node (PDSN)        establish the link layer (PPP) connection and then perform the        Mobile IP registration procedures over the link layer (PPP)        connection.    -   10. After completion of Mobile IP registration, the mobile        system can send/receive data via GRE framing over the A10        connection.    -   11. The Packet Control Function (PCF) periodically sends an        A11-Registration Request message for refreshing registration for        the A10 connection.    -   12. For a validated A11-Registration Request, the Packet Data        Serving Node (PDSN) returns an A11-Registration Reply message.        Both the Packet Data Serving Node (PDSN) and the Packet Control        Function (PCF) update the A10 connection binding record.

For a circuit -switched voice call, the additional elements shown inFIG. 3B are required. In particular, the packet -switched voice receivedfrom the wireless device (MS) is forwarded from the Packet Data ServingNode (PDSN) to the Media Gateway (MGW) where it is converted to circuit-switched voice and delivered to the Public Switched Telephone Network(PTSN). In addition, call setup data is exchanged with the SessionInitiated protocol Proxy Server (SIP) to provide a signaling and callsetup protocol for IP-based communications that can support a supersetof the call processing functions and features present in the PublicSwitched Telephone Network (PSTN). The Media Gateway Control Function(MGCF) and the Signaling Gateway (SGW) implement the call processingfeatures present in Signaling System 7 (SS7).

FIG. 4 illustrates, in block diagram form, the architecture of animplementation of the Aircraft Mobile IP Address System which providesmobile IP addresses within the EVDO Network described above. The PublicData Switched Network 401 is connected via the radio frequency links ofa plurality of Cells 421, 422 to the Air-to-Ground Communications Unit402 (part of the Aircraft Interface 209 of FIG. 2) and then to theAir-to-Ground Control Processing Unit 403 (part of the AircraftInterface 209 of FIG. 2). The Air-to-Ground Communications Unit 402includes a plurality of Air-to-Ground Modems 411, 412 for terminatingthe radio frequency links maintained by Cells 421, 422. TheAir-to-Ground Communications Unit 402 also includes a Mobile IP Client413. The radio frequency design for the Air-To-Ground Modem typicallyuses multiple modems, where one Air-To-Ground Modem (Air-to-Ground Modem411) operates with a Vertical signal polarization and one Air-To-GroundModem (Air-to-Ground Modem 412) operates with a Horizontal signalpolarization; and as signal strength is lost/gained on the individualAir-To-Ground Modems, that Air-To-Ground Modem becomes dormant oractive.

In this embodiment, the Air-To-Ground Modems 411, 412 are not assignedan IP address, but the Mobile IP Client 413 on the Air-To-GroundCommunications Unit 402 is assigned a single IP address with a ForeignAgent 416 on the Public Data Switched Network 401. This Mobile IP Client413 is configured with a Home Address 414 and registers with acorresponding Foreign Agent 416/Home Address 414 to associate a HomeAddress with Air-To-Ground Modem 411 or Air-To-Ground Modem 412 on thePublic Data Switched Network 401. The Home Address 414 to Care ofAddress 415 (subnet address) association does not change, since the Careof Address 415 is the Public Data Switched Network 401 IP address and ismanaged in the Public Data Switched Network 401. The Mobile IP Client413 on the Air-To-Ground Communications Unit 402 requires informationfrom the Air-To-Ground Modems 411, 412 to update Mobile IP bindings onForeign Agent 416/Home Address 414. The Mobile IP Client 413 mustreceive both of the Air-To-Ground Modem 411 and Air-To-Ground Modem 412Assigned IP addresses (this is the Care of Address for the Mobile IPClient 413). The Mobile IP Client 413 shall have configured/known HomeAddress 414 and Home Agent Server Address 419. This configuration canrun multiple Mobile IP Clients and tunnels on the Air-To-GroundCommunications Unit 402.

FIG. 5 illustrates, in block diagram form, the architecture of animplementation of the Aircraft Mobile IP Address System which providesmobile IP addresses outside of the EVDO Network using a Mobile IP tunnelIn this second embodiment of the protocol, the Air-To-Ground Modems 511,512 are each assigned an IP address, and the Mobile IP Client 513resides on the Air-To-Ground Control Processor Unit 503. This Mobile IPClient 513 is configured with a Home Address 514, and corresponding Careof Addresses 515, 516 are associated with Air-To-Ground Modem 511 andAir-To-Ground Modem 512, respectively, in the Air-To-GroundCommunications Unit 502. The Mobile IP Client 513 on the Air-To-GroundControl Processor Unit 503 is connected via a Mobile IP Tunnel 514 tothe Public Data Switched Network 501. The radio frequency design for theAir-To-Ground Modem typically uses multiple modems, where oneAir-To-Ground Modem (Air-to-Ground Modem 511) operates with a Verticalsignal polarization, and one Air-To-Ground Modem (Air-to-Ground Modem512) operates with a Horizontal signal polarization; and as signalstrength is lost/gained on the individual Air-To-Ground Modems, thatAir-To-Ground Modem becomes dormant or active.

This implementation uses a Mobile IP Client 513 on the Air-To-GroundControl Processor Unit 503 and no Foreign Agent since the Care ofAddresses 515, 516 are configured on the Mobile IP Client 513, which isbeyond the Home Address 514 and Home Agent Server 519 address. Inoperation, the single Mobile IP Client 513 registers with Home Agent 504and can utilize the Care of Addresses 515, 516 of either Air-To-GroundModem 511 or Air-To-Ground Modem 512. When the single Mobile IP Client513 is registered, the Home Agent 504 has a Mobile IP tunnel 504 to Careof Address 1 (515) on Air-To-Ground Modem 511 or Care of Address 2 (516)on Air-To-Ground Modem 512. The Mobile IP Client 513 on theAir-To-Ground Control Processor Unit 503 requires information from theAir-To-Ground Communications Unit 502 to update Mobile IP bindings onHome Agent Server 519. The Mobile IP Client 513 must receive the IPaddresses assigned by the Air-To-Ground Modem 511 and the Air-To-GroundModem 512 (this is the Care of Address 515, 516 for the Mobile IP Client513. The Mobile IP Client 513 has configured/known Home Address 514 andHome Agent Server Address 519. There is a Mobile IP Tunnel 504 perAir-To-Ground Modem 511, 512, or a Mobile IP Tunnel 504 per WiFi Client.

FIG. 6 illustrates typical addressing used in the system of FIG. 5, andFIG. 7 illustrates the transfer of an IP Tunnel between Air-to-GroundModems with the resulting change in typical addressing that isillustrated in FIG. 6. In these Figures, there are data streams arrivingat the Public Data Switched Network 501 which consist of a data Payloadand a prepended destination address of DIP=HA.A and DIP=HA.B. As thesedata streams are transported in the MIP Tunnels 514A and 514B, anaddress, consisting of the Care of Address CoA.1 and CoA.2,respectively, as well as a Generic Routing Encapsulation GRE, isprepended to the data streams. Once received at the Air-To-GroundControl Processor Unit 503, these data streams have the new addressheaders stripped off and the original addressing is restored. In FIG. 7,the one MIP Tunnel is routed via the Air-To-Ground Modem 511 with theresultant addressing changes in the prepended address used in the MIPTunnel of DIP=CoA.2 becoming DIP=CoA.1 for this flow.

FIG. 8 illustrates, in block diagram form, the architecture of animplementation of the Aircraft Mobile IP Address System which providesmobile IP addresses outside of the EVDO Network using IP tunnels. Inthis third embodiment of the protocol, the Air-To-Ground Modems 811, 812are each assigned an IP address, and Simple IP Addresses are managed onthe Air-To-Ground Communications Unit 802. Multiple IP Tunnels 805, 806connect the Air-To-Ground Control Processor Unit 803 to a Router 804 inthe ground-based Access Network. The Air-To-Ground Control ProcessorUnit 803 performs the tunnel endpoint functions and uses a PublicAddress 813 for these IP Tunnels 805, 806. The traffic is switchedbetween the two Air-To-Ground Modems 811, 812 as signal strength islost/gained on the individual Air-To-Ground Modems 811, 812.

FIG. 8 is an example of provision of a mobile IP address outside of theEVDO Network. Both Air-To-Ground Modems 811, 812 are traffic modemswhere both connect and attempt to establish sessions/connections. EachAir-To-Ground Modem 811, 812 has a Simple IP address assigned to it,which is routable within the Aircraft Network. As with the systemsdescribed above, the radio frequency design for the Air-To-Ground Modemtypically uses multiple modems, where one Air-To-Ground Modem(Air-to-Ground Modem 811) operates with a Vertical signal polarization,and one Air-To-Ground Modem (Air-to-Ground Modem 812) operates with aHorizontal signal polarization; and as signal strength is lost/gained onthe individual Air-To-Ground Modems, that Air-To-Ground Modem becomesdormant or active.

The Air-To-Ground Control Processor Unit 802 performs Tunnel EndpointFunctions as defined in the industry standards documents and requiresthat a Tunnel Endpoint Public Address 813 be configured on the TunnelEndpoint Client 807 executing on the Air-To-Ground Control ProcessorUnit 803. The Air-To-Ground Control Processor Unit 803 can tunnel dataover Air-To-Ground Modem 811 and/or Air-To-Ground Modem 812, based onAir-To-Ground Modem performance data (SINR, Sector Loading, etc.). Atthe ground-based terminus of this link, the Router 804 performs theTunnel Endpoint 808 functions. Alternatively, a Server 808 can beimplemented in the Core Network of FIGS. 3A and 3B to implement theTunnel Endpoint functions.

The Server 808 is in the Core Network, and the Client 807 is on theAir-To-Ground Control Processor Unit 803. The IP data transmitted overthis link appears no different with respect to application content fromIP data not transmitted over this link. The Client 807 processes packetsjust prior to transmission and is the first to process packets uponreception such that the tunneling protocol is transparent to higherlevel software. Thus, the WiFi Client IP Address maintained afterpassing through the Tunnel(s) is transparent multiple IP tunneling. Allfragmentation and reassembly of data are easily handled because the TCPsessions are terminated at the Client 807 and Server 808. Only datapasses through the tunnel, and the packet boundaries used within thepackets transmitted through the tunnel have no relationship to theoriginal TCP/IP packetization. Therefore, TCP/IP fragmentation betweenthe WiFi client and Client 807 is completely isolated from the TCP/IPconnection between the Sever 808 and the origin server and vice-versa.Data may be fragmented between the Server 808 and origin server, andthis fragmentation has no effect on the TCP connection between theClient 807 and the WiFi client.

SUMMARY

The Aircraft Mobile IP Address System enables the assignment ofindividual Internet Protocol (IP) addresses to each of the passengerwireless devices, operating in an aircraft and served by an airbornewireless cellular network, thereby to enable delivery of wirelessservices to the individually identified wireless devices.

What is claimed as new and desired to be protected by Letters Patent ofthe United States is:
 1. An Aircraft Mobile IP Address System forproviding individual ground-based IP addresses to a plurality ofpassenger wireless devices which are located onboard an aircraft,comprising: aircraft network means, located in said aircraft, forgenerating radio frequency communication signals to communicate with atleast one of said plurality of passenger wireless devices located insaid aircraft; ground-based Access Network means for exchangingcommunication signals with at least one ground-based communicationnetwork; and Air-To-Ground network means for radio frequencycommunications between said aircraft network means and said ground-basedAccess Network means for transmitting data packets, independent of themultiple IP addresses associated with the multitude of passengerwireless devices on the aircraft, between said aircraft network meansand said ground-based Access Network means.
 2. The Aircraft Mobile IPAddress System of claim 1 wherein said Air-To-Ground network meanscomprises: data concentrator means, located on said aircraft, forconverting the subscriber traffic and signaling channels received fromsaid plurality of passenger wireless devices located in said aircraft toat least one aggregate data stream.
 3. The Aircraft Mobile IP AddressSystem of claim 1 wherein said Air-To-Ground network means comprises:data disaggregation means, located in said ground-based Access Networkmeans, for disaggregating said at least one aggregate data stream into aplurality of data streams and delivering each of said plurality of datastreams to a corresponding ground-based communications network.
 4. TheAircraft Mobile IP Address System of claim 1 wherein said Air-To-Groundnetwork means comprises: Mobile IP Client means, located in saidaircraft, for housing a Home Address on said aircraft to communicatebetween said aircraft network means and said ground-based Access Networkmeans.
 5. The Aircraft Mobile IP Address System of claim 4 wherein saidAir-To-Ground network means further comprises: a plurality ofAir-to-Ground Modem means for implementing said radio frequencycommunications in complementary polarizations.
 6. The Aircraft Mobile IPAddress System of claim 1 wherein said Air-To-Ground network meanscomprises: Mobile IP Client means, located in said aircraft, for housinga Home Address on said aircraft to communicate between said aircraftnetwork means and said ground-based Access Network means.
 7. TheAircraft Mobile IP Address System of claim 6 wherein said Air-To-Groundnetwork means further comprises: a plurality of Air-to-Ground Modemmeans, each having an IP address, for implementing said radio frequencycommunications in complementary polarizations.
 8. The Aircraft Mobile IPAddress System of claim 6 wherein said Air-To-Ground network meansfurther comprises: Mobile IP Tunnel means for transmitting data packets,independent of the multiple IP addresses associated with the multitudeof passenger wireless devices on the aircraft, between said aircraftnetwork means and said ground-based Access Network means.
 9. TheAircraft Mobile IP Address System of claim 1 wherein said Air-To-Groundnetwork means comprises: IP Tunnel means for transmitting data packets,independent of the multiple IP addresses associated with the multitudeof passenger wireless devices on the aircraft, between said aircraftnetwork means and said ground-based Access Network means.
 10. TheAircraft Mobile IP Address System of claim 9 wherein said Air-To-Groundnetwork means further comprises: a plurality of Air-to-Ground Modemmeans, each having an IP address, for implementing said radio frequencycommunications in complementary polarizations.
 11. The Aircraft MobileIP Address System of claim 9 wherein said ground-based Access Networkmeans comprises: router means, located on said ground, for hosting atunnel endpoint function for said IP Tunnel means.
 12. The AircraftMobile IP Address System of claim 1 wherein said Air-To-Ground networkmeans further comprises: Air-to-Ground Control Processor means, locatedon said aircraft, for hosting a tunnel endpoint function for said IPTunnel means.